Inspection door and like closure



A ril 4-, 1939. J. F. e. CHOBERT 3 INSPECTION DOOR AND LIKE CLOSUREFiled Nov. 21, 1936 2 Sheets-Sheet l v fvwenl 'ar c?zza9 62,0167? v 20*hung 4 flZY'ornqys.

April 1939- J. F. a. CHOBERT 2,153,073

INSPECTION DOOR AND LIKE CLOSURE Filed Nov. 21, 1936 2 Sheets-Sheet 23nventor Patented Apr. 4, 1939 INSPECTION DOOR AND LIKE CLOSURE JacquesFrancois Gabriel Chobert, Saint-Etienne, France Application November 21,1936, Serial No. 112,181 In France December 3, 1935 7 Claims.

The present invention relates. to inspection doors and like closures formachinery, aircraft and vehicles.

An object of the present invention is to pro- 5 .vide an inspection doorwhich is easily operated by hand and may be quickly opened and closed. Afurther object is to provide a door which may be made of thin lightmaterial, constructed in such a way as to prevent the reduced rigidityof such material causing the door to fit badly or distort under thestresses set up when in use. Means are provided for securing the door inthe locked position.

According to the present invention an inspection door comprises a fixedframe, a closure plate hinged to said frame in a manner to allowmovement of said closure plate in its own plane relatively to the frameas well as movement about the hinge, a number of fastening devicescarried by such relative movement in one sense to secure the closureplate at a number of points and spring means acting to maintain theclosure plate in the locked position.

In one form of construction a circular closure plate is arranged forrotation about its centre and also for movement about a hinge and isprovided with a number of fastening devices adapted to engage parts ofthe frame on rotation of the plate in one sense and said closure plateis given a spring bias to maintain it in the locked or free position.

In a modified constructional form a rectangular closure plate is mountedon the arm of a hinge 35' by means permitting sliding of the platerelatively to the frame to engage or disengage fastening devices andspring means act to secure the plate in the locked position.

Constructional forms for circular and rectangular doors are describedwith reference to the accompanying drawings, in which:--

Figs. 1 to 7 show the invention applied to circular doors; Fig. 1 beinga view of a door from the exterior, Fig. 2 an interior view, Fig. 3 asectional perspective view and Fig. 7 a section on the line VII-VII ofFig. 2. Figs. 4, 5 and 6 illustrate a modified fastening and hingearrangement; Fig. 4 being an interior View, Fig. 5 a sectionalperspective view on the line VV of Fig. 4 with the bridge removed, andFig. 6 an enlarged detail view of one of the fastening devices.

Figs. 8 to 11 show this invention applied to rectangular doors; Figs. 8and 9 being views from the exterior showing the door unlocked andlocked, and Figs. 10 and 11 being side vertical said plate andcooperating with the frame upon sectional views showing means forlocking the closure plates in position, Fig. 11 being taken on the lineIIII of Fig. 9.

Referring to Figs. 1 to 3 and Fig. '7 an inspection door has a frame Iof Z cross-section adapted to be mounted on and secured to a part II ofa vehicle or the like. A circular closure plate I2 is attached, at itscentre, to said frame II] by means of a pin joint I5, hinge arm I6 and ahinge II, the arrangement being such that the closure plate I2 iscapable of movement about the hinge axis and also of rotation about itscentre relatively to the hinge arm I6. A bridge piece I8 spans the hingearm I6 and ensures that the closure plate follows movements of the hinge15 arm about the hinge and at the same time allows a degree of freedomof rotation of-said closure plate limited by the ends of the bridgepiece I8 which form end stops.

The inner flange of the Z cross-section frame I0 is provided withnotches I91, I92, etc., which cooperate with latching members I41, I42,etc., to secure the closure plate I2 to the frame Ill. The latchingmembers I41, I42, etc., consist of truncated conical members carried oncentral spindles mounted on the closure plate I2 (see Fig. 3). In thefree position these latching members I41, I42, etc., are adapted to passthrough the notches I91, I92, etc. when in this position, rotation ofthe closure plate I2 by means of a knob I3 causes it to be secured totheframe I0.

Wedgin-g action of the latching members I41. I42, etc., on rotation ofthe closure plate I2 causes it to be pressed firmly on the flange of theframe 5 I0, and the multiplicity of such members, of which five areshown in the drawings, ensures that the closure plate does not gapeunder the influence of internal pressures.

A locking device for a door as above described comprises a spring 24, 25which acts to maintain the hinge arm I6 in either of its extremepositions of travel under the bridge piece I8. The spring is attached tothe hinge arm I6 by a slot 29 therein and to the bridge piece I8 by ahole 23 in an upturned flange formed thereon (see Fig. '7). The slot 29is provided with a circular port 2| at one end. The arrangement is suchthat the spring provides a toggle action which tends to prevent rotationof the closure plate I2 under the influence of vibration by giving theplate a bias in the direction of either one of the arrows f1 or f2 as itis in one or the other of its extreme! positions.

The arrangement of the closure plate I2 and 2 section frame H0illustrated in Fig. 3 reduces the projecting parts to a minimum and thusreduces aerodynamic drag when the inspection door is used on theexterior of aircraft for example.

A modified construction is illustrated in Figs. 4 to 6. The form of thehinge and hinge arm is arranged to eliminate projecting parts of thehinge on the exterior surface and also a modified form of latchingmember is incorporated.

A hinge plate 3|] is secured to the frame I 0 and is provided withraised wings 321, 322 which project on the interior of the door andcooperate with a hinge arm 28 to locate the closure plate correctlyprior to securing same and prevent the said hinge arm 28 from turningduring the freeing and securing movements of the closure plate. To allowthe hinge plate 30 to be fixed on the interior of the door, the hingearm 28 is arched at 29 as shown in Figs. land 5 and the pin thereof islocated outwardly of the edge 3| of the closure plate.

The latching members in this form of construction comprise stamped outmembers 261, 262 etc., as illustrated in Fig. 6 adapted for attachmentto the closure plate l2. In the free position these members are adaptedto pass through notches 271, 212 etc., in the flange of the frame l6. Onrotation of the closure plate I2 from this position the latching members261, 262 etc., cooperate with parts of the flange I0 to provide awedglng action whereby the closure plate I2 is drawn towards and securedto the frame ID.

A locking device similar to that described with reference to andasillustrated in Figs. 2 and '7 may be used with this form ofconstruction as illustrated in Fig. 4.

This invention may be applied to doors of shapes other than circular andis illustrated in Figs. 8 to 11 as applied to a rectangular door.

A closure plate 62 is attached to a frame 6| of Z cross-section by meansof hinges 611, 612 having hinge arms 661, 662 provided with slots 681,682 etc., which engage headed studs 691, 692 etc., mounted on theclosure plate 62. The slots 681, 682 etc., permit'movement of theclosure plate relative to the hinge and frame in a direction parallel tothe hinge axis in addition to the normal hinge movement.

The frame SI has notches 631, 632 etc., adapted to engage latchingmembers 651, 652 etc., mounted on the closure plate 62 when said plateis moved relatively to the hinge arms 661, 662. The latching members651, 652 etc., are similar to those shown in. Fig. 3 and comprisetruncated conical members carried on central spindles mounted on theclosure plate 62.

Figs. 8 and 9 show the closure plate in the unlocked and lockedpositions respectively and it will be noted that to secure the-closureplate 62 it is displaced upwards.

Two ways of maintaining the closure plate 62 in the locked position areillustrated in Figs. 10 and 11. The closure plate 62, in each case, isprovided with an auxiliary part corresponding in width to the length oftravel due to the slots 681,

682 etc., said part being interposed between the flange at the lower endof the frame and the lower end of the closure plate to maintain saidplate in the locked position.

In the arrangement illustrated in Fig. 10 a plate I0 is attached by ahinge 'II to the lower end of the closure plate 62 and is provided withquick release clips 12 to hold it in position to secure the plate 62.Fig. 11 shows an alternative arrangement in which the hinged plate I0 isreplaced by a removable member I3 which may be held in position by clips12.

What I claim is:

1. An inspection door comprising a fixed frame, a closure plate hingedto said frame in a manner to allow movement of said closure plate in itsown plane relatively to the frame as well as movement about the hinge, anumber of fastening devices carried by said plate and cooperating withthe frame upon such relative movement, in one sense, to secure theclosure plate at a number of points and spring means acting to maintainthe closure plate in the locked position.

2; An inspection door as claimed in claim 1 including fastening devicescomprising truncated conical members carried on spindles mounted on theclosure plate, adapted to pass through notches in the frame and adaptedupon movement of the closure plate in its own plane to engage solidparts of the said frame.

. 3. An inspection door as claimed in claim 1 including fasteningdevices having cambered surfaces adapted to engage the frame with aprogressive tightening effect as the closure plate is moved in one sensein its own plane.

.4. An inspection door comprising a fixed frame, a circular closureplate mounted to said frame by a hinge permitting rotation, relativelyto the frame, of said plate about its centre, a number of fasteningdevices carried by the plate and 00- operating with the frame upon suchrelative movement, in one sense, to secure the closure plate at a numberof points and spring means arranged so as to resist initial rotationalmovements of the closure plate from the locked position.

5. An inspection door as claimed in claim 4 including stops acting tolimit the rotational movement of the closure plate and spring meanscomprising a U-shaped spring arranged to bias the, closure plate towardsthe locked and unlocked positions.

6. An inspection door comprising a fixed frame, a closure plate mountedto said frame on a hinge, means permitting sliding movement of theclosure plate relatively to the frame, a number of fastening devicesadapted to engage the frame upon such movement and a member adapted tomaintain the closure plate in the secured position'and quick releasespring clips to lock the closure plate in this position.

7. An inspection door as claimed in claim 6 including a member forlocking the closure plate adapted to be interposed between a part of theframe and the closure plate when the latter is in the secured position.

JACQUES FRANCOIS GABRIEL CHOBERT.

